For those who record and produce music on computers,
weve given Onyx mixers another worlds first 
an optional user-installable 24-bit/96kHz FireWire I/O card with the ability
to send up to 16 individual channels of high-quality digital audio direct
to any FireWire-equipped computer (Windows XP or Mac OSX.3 or later).
The FireWire card also sends a Left/Right stereo quick mix
to the computer, with a level trim control that boosts or cuts the mix
by ±10 dB as it is sent to the card  again letting you set
levels independently for the live L/R mix and the recorded tracks.

Better still, the FireWire interface returns two channels of audio from the
computer to the mixer, letting you monitor your computer through the control
room/phones matrix (pictured at left). So with FireWire, Onyx mixers can record
everything from live gigs to studio sessions, with higher quality and lower
latency than many dedicated computer audio interfaces. (In fact, an Onyx 1640
mixer with FireWire rivals the specifications and performance of dedicated studio
A/D converters costing more than the entire Onyx 1640 mixer. Not to mention
giving you waaaay more channels and flexibility.)